Many applications require sensing of a temperature to effectuate a task. One typical way of sensing a temperature is to place a temperature sensor within the environment to be sensed. The temperature sensor conveys an electrical signal, which is indicative of the temperature of the environment, to electrical conversion circuitry which converts the electrical signal into a temperature and subsequently displays it to a user. A problem often arises, however, in that many conventional prior art temperature sensing solutions do not provide for highly accurate temperature readings because the sensors are not adequately calibrated for use with the electrical conversion circuitry.
One prior art solution to this problem was to calibrate a given sensor over a temperature range by placing general calibration information into a memory associated with the conversion circuitry. This general calibration information suffered from the drawback that each sensor in use is not identical, but rather has its own internal variations. Therefore, the general calibration data used within the electrical conversion circuity did not provide for an accurate temperature reading for any one particular sensor.
Another solution involved calibrating a given sensor over a number of different temperatures and storing calibration information within a memory associated with the electrical conversion circuitry. In this manner, the sensor was calibrated and had unique calibration information associated with it in the electrical conversion circuitry. This solution, however, suffered from the drawback that the useful life of a sensor is often substantially shorter than the useful life of the conversion circuitry. Therefore, when a sensor needed to be replaced, the unique calibration information within the electrical conversion circuitry was no longer applicable to a replacement sensor. Whenever a sensor needed to be replaced (which was frequent), a user needed to replace both the sensor and the substantially more expensive electrical conversion circuitry. This resulted in high cost and expense to the user.
In addition to the above prior art limitations, prior art methods of calibrating a sensor consisted of using linear approximations to characterize a sensor over a temperature range. In this manner, typical linear conversion methodologies such as look-up tables were utilized, but the linear approximations provided poor accuracy since temperature sensors do not behave linearly over a broad range of temperatures. Therefore, even when a sensor was calibrated, its calibration consisted of inaccurate linear approximations.